The invention relates generally to cylindrical objects movable in cylindrical bores, and more particularly, to pistons reciprocal in cylinders.
When a first work object in contact with a second work object is caused to move relative to the first work object, such as when a piston reciprocates in a cylinder, and when little or no lubrication is provided to reduce friction between the first work object and the second work object, wear of both the first and second work objects occurs.
Attention is directed to the following U.S. Patent references which relate to pistons: